Flight from San Francisco to Chongqing late evening depart mid-day next day to Seoul, Korea

I will only be in Chongqing for 12 hrs - leaving the airport to stay in a local hotel and returning around 11am for departure to Seoul. What I am reading is that I can get a 72 hr free transit without any cost by just notifying the airline to alert the customs in Chongqing. The Chinese Consulate in San Francisco is trying to tell me I need to purchase a $140 visa. Has anything changed recently?